Does the relay right behind the power meters switch "click" when switching from normal to class A ?
Well..:scratch2: Replace the two fuses. And we will go from there.
These fuses are for the un regulated B+/- voltage for both Class AB and A.
Check the voltages around TR221You know what the relay behind meters, it is not engaging.
Check the voltages around TR221
E---8.9vdc
B---8.25vdc
C---8.85vdc
I assume you are referencing the wires coming off the power board. since those have labels e, b, c correct?
No. I'm referring to the emitter, base and collector of TR221.
No. I'm referring to the emitter, base and collector of TR221.
Might have a welded relay..Or a broken or dirty mode switch.
You know what the relay behind meters, it is not engaging. The one on the power board is though.
Think I have a bit of work ahead of me.
The relay behind the meters is new, and engages in normal class.
The relay on the power board was not changed out, and it engages when set at class A
I will look over the switch.
Check the photo again.. And measure the resistance across the switch contacts ( Without power applied!).. Measure both positions (Class A/ Normal).. Class A should show continuity.. Normal should read "open"
http://www.audiokarma.org/forums/showpost.php?p=6673962&postcount=86
You said the relay was not engaging !
Forget the "mode switch " apparently its working.
Have you tried adjusting class A bias after replacing the 10A fuses?
Behind meter relay is strickly for Normal/Class A rail voltage switching
Relay on the power board is "speaker protection" and should "set" or "reset" in either modes.
When Class A set the relay on the power board engages not the front.
Yes Class A is adjustable now
Hallalluya... disreguard post #98.. Anymore issues?